SSEN Transmission has published its 2025/26 Annual Performance and Sustainability Reports, highlighting continued progress in delivering infrastructure to support energy security, economic growth and clean power across the UK.

Covering the 2025/26 year, the reports also mark the end of the five-year RIIO-T2 price control. Since 2021, the company says it has grown and transformed the electricity transmission network across the north of Scotland as it prepares for unprecedented levels of investment.

The Annual Performance Report shows the business closed RIIO-T2 having invested more than £6bn in the transmission network, maintained 99.999% network reliability, delivered every connection offer on time, connected significantly more renewable generation than first planned, and outperformed its £100m efficiency target, with over £240m of efficiencies expected to benefit consumers.

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Growth during RIIO-T2 included increasing connected renewable generation from 6.75GW to 10.8GW, expanding the value of transmission assets from £2.97bn to £6.63bn, cutting operational greenhouse gas emissions by 31%, and growing the workforce from 719 colleagues to more than 2,800 by the end of the period.

Looking ahead, the reports set out progress during 2025/26 on SSEN Transmission's £29bn investment programme. Around 75% of major consents across the plan are now in place, construction is advancing on key schemes including Eastern Green Link 2 and the Orkney Link, and work has commenced at both the Netherton and Banniskirk Hubs.

The Annual Sustainability Report details further outcomes: enough renewable electricity was transmitted to power 12.7 million homes; a sector-leading SF6 leakage rate of 0.10% was achieved; more than 19% Biodiversity Net Gain was delivered; roughly £3m was awarded through community benefit funds; over 600 homes were supported through the company's housing strategy; and stakeholder engagement remained industry-leading.

Rob McDonald, Managing Director of SSEN Transmission, said: "The close of RIIO-T2 marks an important milestone for our business. Over the last five years, we've delivered significant value for consumers, customers and communities while building a strong foundation for the unprecedented investment now underway across the north of Scotland. I'm incredibly proud of what our people, partners and stakeholders have achieved together, and excited about the opportunity ahead as we continue delivering the network needed for a secure, affordable and clean energy future."

The Annual Performance Report and Annual Sustainability Report are available to read on SSEN Transmission's website.